- In a small saucepan, bring the vinegar, sugar and ginger to a boil, stirring until the sugar has dissolved. Remove from the heat. Add the soy sauce and sesame oil. Set aside.
- In the bowl of a food processor, finely chop the shrimp and garlic with the egg. Add the remaining ingredients and pulse for a few seconds until it forms a smooth paste. Transfer that mixture to a bowl.
- On a work surface, lay six squares of dough at a time. With a spoon, place about 15 ml (1 tablespoon) of filling in the centre of each square. Brush the dough with a little water. Bring the dough up around the filling without closing the dumpling completely. Transfer to a refrigerated baking sheet and repeat with the remaining ingredients.
- Oil the top part of a steamer or line a bamboo basket with parchment paper. Arrange about a third of the dumplings in the steamer, without touching. Steam over a pan of boiling water for about 10 minutes. Transfer to a warm serving dish. Continue cooking the remaining dumplings. Serve with the sauce.
The wonton dough is sold in the frozen food section in most grocery stores. You can sometimes find frozen siu mai dough, although it is primarily found in Asian grocery stores.
The dumplings can be frozen before cooking. To do this, place them separately on a baking sheet lined with parchment paper and cover. Freeze and transfer the dumplings to an airtight container. No need to thaw them before steaming. Count on about 10 minutes of steaming.